ENZYMATIC PRODUCTION OF FRUCTOSE
Production of fructose from saccliarides by processes, in which fructose 6-phosphate phosphatase (F 6 PP) catalyzes the conversion of fructose 6-phosphate (F 6 P) to a fructose, in the presence of one or more divalent cations, Mg 2+ , Zn 2+ , Ca 2+ , Co 2+ , and Mn 2+ , are disclosed herein.
1 . A process for preparing fructose from a saccharide comprising:
a step of converting fructose 6-phosphate (F 6 P) to a fructose catalyzed by fructose 6-phosphate phosphatase (F 6 PP) in the presence of a divalent cation selected from the group consisting of Mg 2+ , Zn 2+ , Ca 2+ , Co 2+ , Mn 2+ , and combinations thereof.
2 . The process of claim 1 , wherein the step of converting F 6 P to fructose catalyzed by F 6 PP is in the presence of Mg 2+ and a divalent cation selected from the group consisting of Zn 2+ , Ca 2+ , Co 2+ , Mn 2+ , and combinations thereof.
3 . The process of claim 1 , wherein the concentration of the divalent cation ranges from 0.01 mM to 500 mM.
4 . The process of claim 1 , wherein the divalent cation is Co 2+ or Mn 2+.
5 . The process of claim 1 , wherein the divalent cation is Co 2+ .
6 . The process of claims 1 , wherein the divalent cation is Mn 2+ .
7 . The process of claim 1 , further comprising a step of converting glucose 6-phosphate (G6P) to the F 6 P, wherein the step is catalyzed by phosphoglucoisomerase (PGI).
8 . The process of claim 7 , further comprising the step of converting glucose 1-phosphate (G1P) to the G6P, wherein the step is catalyzed by phosphoglucomutase (PGM).
9 . The process of claim 1 , wherein the saccharide is selected from sucrose, starch, or a starch derivative selected from the group consisting of amylose, amylopectin, soluble starch, amylodextrin, maltotriose, maltodextrin, maltose, and glucose.
10 . The process of claim 9 , further comprising the step of converting the saccharide to the G1P, wherein the step is catalyzed by at least one enzyme.
11 . The process of claim 10 , wherein the at least one enzyme in the step of converting a saccharide to the G1P is selected from the group consisting of alpha-glucan phosphorylase (αGP), maltose phosphorylase, and sucrose phosphorylase, and mixtures thereof.
12 . The process of claim 11 , wherein the saccharide is starch, further comprising the step of converting starch to a starch derivative wherein the starch derivative is prepared by enzymatic hydrolysis of starch or by acid hydrolysis of starch.
13 . The process of claim 11 , wherein 4-glucan transferase (4GT) is added to the process.
14 . The process of claim 12 , wherein the starch derivative is prepared by enzymatic hydrolysis of starch catalyzed by isoamylase, pullulanase, alpha-amylase, or a combination thereof.
15 . The process of claim 1 , wherein the process steps are conducted at a temperature ranging from about 37° C. to about 95° C., at a pH ranging from about 5.0 to about 8.0, and/or for about 8 hours to about 48 hours.
16 . The process of claim 1 , wherein the process steps are conducted in a single bioreactor.
17 . The process of claim 1 , wherein the process steps are conducted ATP-free, NAD(P)(H)-free, at a phosphate concentration from about 0.1 mM to about 150 mM, the phosphate is recycled, and/or at least one step of the process involves an energetically favorable chemical reaction.